I was just thinking about that. Does it just affect one dungeon at a time or all of them at once? Do they just change the layouts of each floor, or do they change the numbers of them, as well? I don't recall a lot of this being explained the first time it happened in this series, so there's still plenty of room to explore in its world-building.
Without going back to reread those chapters, what I
recall is that it should just be a localized event, a rare phenomenon, changes the order of the floors, and perhaps also makes minor changes to any given floor's layout.
This of course was a
big deal when it happened in Tower City on account of the dungeon being, you know, a tower. So things would have been someone grander in scale here, since overall shuffling 5 floors around can't compete in terms of impact.